Colas Rail is a railway infrastructure and rail freight company primarily active in the United Kingdom. It is a subsidiary of the French industrial group Bouygues. Colas Rail was originally created as Seco Rail, named after its then-parent company SECO (Société d'Études et de Construction d'Outillage). In the twentieth century, its main activities were railway construction and maintenance. Seco Rail participated in various major projects, such as in the construction of phase one of High Speed 1. During 2006, it became a rail freight operator in the British market, initially transporting aggregates using leased rolling stock. Seco Rail acquired its first locomotives and regular freight customer, Kronospan, during the following year. In early 2008, Colas Group opted to reorganise its rail s